1. Field of the Invention
The present invention relates generally to a lens barrel of a camera, etc. and, more particularly, to a lens barrel with an improved structure for fitting a lens unit.
2. Related Background Art
Generally, a lens barrel of a camera, etc. is constructed of a plurality of lens elements disposed at an interval in a direction along an axial line of the lens barrel.
Then, in the thus constructed lens barrel, with respect to an external diameter of a male screw of a lens holding frame for fixing the lenses incorporated from one direction, the external diameter of the lens holding frame positioned inside and therefore incorporated at first is minimized, but the external diameter becomes larger with a more approach to the outside.
With this construction taken, the lens holding frame for fixing the lenses can be incorporated sequentially from the inside to the outside.
In recent years, however, as in a large-diameter lens, an effective diameter of the lens has tended to increase to improve an optical performance. According to a lens mounting structure in which the external diameter of the lens holding frame positioned inside is minimized, but the external diameter increases sequentially with a more approach to the outside as in the prior art, a problem is that the lens barrel increases in size.